1. Field of the Invention
Devices, systems, and methods consistent with the invention relate to a power supply apparatus for a sliding door in a motor vehicle such as a minivan (a so-called one-box car), wherein the sliding door and a vehicle body are electrically coupled to one another via a power supply line in order to regularly supply electrical power to the sliding door.
1. Description of the Related Art
Heretofore, in a sliding door of a motor vehicle such as a minivan, a structure has been known in which a power supply line is laid extending from a vehicle body to the sliding door in order to regularly supply electrical power and electrical signals to devices such as electric appliances in the sliding door. The power supply line is housed in a protector, which is made of plastic and installed in the sliding door, in a manner such that the power supply line is in a bending state inside the protector in order that expansion and contraction of the power supply line due to opening and closing movement of the sliding door can be absorbed or compensated.
For example, a structure in which a protector has a slit-shaped opening along which a flanged guide portion whose longitudinal cross section has a curved-shape or slanted-shape is formed, in which a power supply line guidance portion is formed on the edge of the flanged guide portion, and is gradually curved or slanted in the height-wise direction, and in which an opening portion for leading out a power supply line is formed adjacent to the power supply line guidance portion such that it is connected to the slit-shaped opening is known from Japanese Unexamined Patent Application, First Publication No. 2003-335188.
With this structure or apparatus, when a protector is secured to a sliding door and a power supply line is drawn out through a slit-shaped opening to a vehicle body side, the power supply line oscillates along the flanged guide portion at a time of opening and closing the sliding door, and smoothly climbs from an end of the slit-shaped opening along the power supply line guidance portion. Therefore, if a power supply line stationary portion at a vehicle body side is located at a position higher than the slit-shaped opening, an opening portion for guiding the power supply line has the same level of height as the power supply line stationary portion when the sliding door is, for example, fully closed. The power supply line is never folded in a U-turn manner with a small diameter in the vertical direction, and therefore, application of excessive bending force to the power supply line can be avoided.
Further, when the sliding door is opened, the power supply line is caught by the power supply line guidance portion and smoothly guided by the flanged guide portion without being tangled. At the same time, the power supply line being drawn out through the slit-shaped opening is rendered curved or slanted and then smoothly bent in the height-wise direction. When the sliding door is fully closed, the sliding door is substantially outwardly separated from the vehicle body. Thus, a bending radius along the flanged guide portion becomes large such that application of excessive bending force to the power supply line can be avoided.
One conventional protector is formed relatively large in a snail-shape in order to prevent the power supply line from being repeatedly bent with a small diameter in a U-turn manner. Namely, the protector is relative large to form such a snail-shape. If such large protectors are used for production, disadvantages in terms of production costs are generated. In addition thereto, since such a large protector is incorporated inside the sliding door, the locations on which other appliances can be provided are limited, thus resulting in poor design in terms of the layout inside the door.